52 J. H. ASHWORTH, B.SC. 



have not hitherto, to my knowledge, been found together in Liverworts, 

 though oil-containing bodies have long been known to occur in 

 them. 1 The oil found in these tubers closely resembles that which 

 Pfeffer found in other Liverworts in its solubility in various reagents, 

 its fluid condition at a temperature of 12°C, the difficulty experienced 

 in its saponification with potash, and in the fact that the oil is not 

 vaporised on heating to 140°C. 



Besides these stalked tubers projecting ventrally into the soil, there 

 are analogous structures formed in the substance of the thallus, which 

 have not hitherto been described. These are produced by the forma- 

 tion of a cellular mass (like that of the inner part of a stalked tuber) 

 between the upper and lower lays of the thallus. The cells of these 

 tuberous masses have the same structure and contents as those in the 

 inner portion of the external tubers. These cellular masses are usually 

 oval in shape, and their average length and breadth are '2 mm. and 

 •15 mm. respectively. They are somewhat flattened dorsoventrally, 

 their thickness being '1 — T5 mm. In several sections, I have found 

 one of these internal masses at the base of the stalk of an ordinary 

 (but small) tuber. This suggests that, possibly, the stalked tuber in 

 question was in process of formation, and that the cells at the base of 

 the stalk were storing up food materials, which would subsequently be 

 passed into the tuber. Internal masses of considerable size occur in 

 other places in the thallus where there is no sign of the formation of a 

 stalked tuber, and these probably always remain in the thallus, and 

 are independent of any external tuber. 



Regarding the function of the tubers, the Synopsis says they should 

 be looked upon as gemmae, and Huge (Flora, 1893, p. 306) suggests 

 that this process of vegetative reproduction is an adaptation to a mode 

 of life in which the plants are subjected to periodic droughts. In 

 support of this view he mentions the fact that the four plants which 

 bear tubers, mentioned in the Synopsis, come from Western Australia. 

 We may regard these tubers as geminse, the inner cells of which have 

 become stored with food materials, and are protected by a corky 

 envelope formed by modification, when the tuber is fully formed, of the 

 cell walls of the outer cell layers. In Anthoceros tuberosus we may 

 presume that the internal cellular masses, as well as the ordinary 

 tubers, can give rise to new plants, and hence if the thallus becomes 

 1 Pfeffer. DieOelk6rperderLebermoo.se. Flora. Jan., 1874. 



